1. Field of the Invention
The present invention relates to apparatus and methods for preventing the escape of fluid from wells or pipes.
2. Description of the Prior Art
As shown by recent events in the Gulf of Mexico, oil well blowouts are a serious threat to the environment, and can be very costly. Current blowout preventers can be unreliable. While there are numerous prior inventions of blowout preventers, none are equivalent to the present invention.
U.S. Pat. No. 1,543,456, issued on Jun. 23, 1925, to Robert Stirling, discloses an early blowout preventer, without the explosive charges of the instant invention.
U.S. Pat. No. 3,548,848, issued on Dec. 22, 1970, to Gerhardt C. Stichling, discloses explosive actuated valves, but does not disclose their use in a blowout preventer as in the instant invention.
U.S. Pat. No. 3,766,979, issued on Oct. 23, 1973, to John T. Petrick, discloses a well casing cutter and sealer, but does not disclose the grooves and tunnels in the plates of the instant invention.
U.S. Pat. No. 3,980,094, issued on Sep. 14, 1976, to Fritz Schröder and Klaus Rössel, discloses a quick action slide valve with a sliding plate, but does not disclose the grooves and tunnels in the plates of the instant invention.
U.S. Pat. No. 4,215,749, issued on Aug. 5, 1980, to Roy R. Dare and Jeff L. Merten, discloses a gate valve for shearing workover lines to permit shutting a well, using a shear plate, but does not disclose the grooves and tunnels in the plates of the instant invention.
U.S. Pat. No. 4,523,639, issued on Jun. 18, 1985, to Roland M. Howard, Jr., discloses ram-type blowout preventers, which a locking mechanism to hold the plate in the channel after the pipe has been cut, but does not disclose the grooves and tunnels in the plates of the instant invention.
U.S. Pat. No. 4,619,284, issued on Oct. 28, 1986, to Jean-Jacques Delarue and Claude Ego, discloses a pyrotechnic valve that may either close an initially open pipe or open an initially closed pipe, but does not disclose its use in a blowout preventer.
U.S. Pat. No. 5,012,854, issued on May 7, 1991, to John A. Bond, discloses a pressure release valve for a subsea blowout preventer that is hydraulically operated. The vents and valves in the instant invention are distinguishable, in that they are not used in a system that is hydraulically operated.
U.S. Pat. No. 5,064,164, issued on Nov. 12, 1991, to Tri C. Le, discloses a blowout preventer with metal inserts resembling the plates in the instant invention, but does not disclose explosive actuation as in the instant invention.
U.S. Pat. No. 5,735,502, issued on Apr. 7, 1998, to Bryce A. Levett and Mike C. Nicholson, discloses a blowout preventer with ram blocks resembling the plates in the instant invention, but it is hydraulically actuated, rather than explosively actuated as in the instant invention.
U.S. Pat. No. 6,354,568, issued on Mar. 12, 2002, to Alec Carruthers, discloses a sliding plate valve, but does not disclose explosive actuation as in the instant invention.
U.S. Pat. No. 6,739,570, issued on May 25, 2004, to Hans-Paul Carlsen, discloses a valve element, which may be used for closing a channel in a blowout preventer, but does not disclose explosive actuation as in the instant invention.
U.S. Patent Application Publication No. 2009/0050828, published on Feb. 26, 2009, to Jeffrey Charles Edwards, discloses blowout preventers with a housing having a throughbore resembling the channel in the instant invention, which may be closed by a pair of opposed rams, but does not disclose explosive actuation as in the instant invention.
British Patent No. 2 175 328, published on Nov. 26, 1986, to Richard Theodore Mitchell, discloses an oil well drilling apparatus, including a blowout preventer stack, without the explosive charges of the instant invention.
Canadian Patent No. 2 506 828, published on Oct. 29, 2006, inventors Dean Foote and Scott Delbridge, discloses a blowout preventer with rams that are hydraulically rather than explosively actuated, as in the instant invention.
Soviet Patent No. 1427057, published Sep. 30, 1988, inventors Y. U. A. Gavrilin, L. M. Torsunov and B. V. Venedictov, discloses a blowout preventer with a flat blocking gate.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.